Morbid fear of Cossacks or pogroms; from Greek Kozako-s ("Cossack") + phobia. By extension, fear of gangs or state-sponsored thuggery.

But often these peasants had nothing but faith and fatalism and flashes of humor to get them through their days, to quell the grinding terror of sudden hoofbeats, of sabers, of Cossacks marauding. This kozakophobia extended even to their everyday objects, or the few preserved today, on which red -- the Cossacks’ color -- was never used; it can be seen, too, in some Russian-language books -- primers, mostly -- preserved from the shtetls, in which every capital 'K' (for Russian 'Kazak', "Cossack") has been blacked out.